Increase In Relative Width Research Articles

Stability and failure mechanisms in three-dimensional cracked slope: Static and dynamic analysis

Three-dimensional limit analysis for seismic stability of slopes with cracks is carried out within the framework of kinematic approach. Three types of failure mechanisms, i.e., the face failure, toe failure and base failure coupled with the most critical cracks are discussed. The sequence quadratic program, associated with a random trials algorithm is applied to search for the least upper bound results of the stability factor (critical height). A validation is carried out for the obtained results, using literature data and outputs from FLAC3D. The effects of slope width and seismic loads on the different failure mechanisms are discussed. Conclusion can be drawn that the width limitation mainly controls the slope failure mechanism. With respect to very narrow spaces, face failure is the most common among the considered failure mechanisms. With increasing seismic coefficient, some cracked slopes, which are prone to toe failure under static conditions, finally collapse dynamically in face failure or base failure mode. The increase in relative width or seismic coefficient will lead to the increasing of the volume of the failure soil mass.

Wave forces on a seawater intake caisson

The wave force on a seawater intake structure consisting of a perforated square caisson of 400 mm×400 mm size encircling a vertical suction pipe of 160-mm diameter is investigated using physical model studies. The porosity of caisson was varied from 1.6 to 16.9%. Regular and random waves of wide range of heights and periods were used. It is found that the force ratio (ratio of the force on perforated caisson to the force on caisson with zero percent porosity) reduces to an extent of up to 60% with increase in porosity of the caisson from 1.6 to 16.9%. The force ratio was found to increase with increase in relative wave height and reduces with increase in relative width. Multiple regression analysis of the measured data points was carried out and predictive equations for wave force ratios are obtained both for regular and random waves. The results of this investigation can be used in the hydrodynamic design of perforated caissons, which are widely used as seawater intake structures.

Allometric Analysis of Relative Humerus Width and Olecranon Length in Some Unspecialized Burrowing Mammals

Regression and allometric analysis show that ground squirrels and other unspecialized burrowers have relatively greater humerus widths and olecranon process lengths as compared to scansorial and relatively unspecialized ambulatory rodents of similar size. If the increase in relative width due to the need for support is similar in all three groups, then the greater humerus width (16 per cent greater) seen in burrowers is due to the need for extra strength to resist environmental loads occurring while digging. Proof for this statement is derived from accurate predictions of humerus widths and olecranon process lengths for mammals of similar size that are distantly related, but with burrowing habits. The increase in relative widths of humeri due to size was considerably less than theoretical considerations would require. Possible reasons for this discrepancy are discussed.